My Droid Bionic has a builtin ICE app with room for at least 2 phone numbers, blood type, and allergies. I have the icon on the my home page. I don't know if it was an app from Google or Motorola. Also, bringing up the People app shows the ICE entry at the top of the first screen. Check your phones, ICE is likely already baked into it.
Of course, if you use a PIN or other lock on your phone, ICE won't help you a bit unless you're able to unlock the phone for the medical folks.
I just checked my lock screen and there is an icon on it for Emergency Contacts, so it seems that someone has thought of everything.